An important goal of the electronics industry is an integration of optoelectronic devices with silicon (Si) substrates through the use of traditional complementary metal-oxide-semiconductor (CMOS) fabrication techniques. It is particularly desirable to develop a means for monolithic heterogeneous integration of direct-bandgap III-V compound materials onto Si CMOS substrates. For example, many important and long-sought-after applications such as optical interconnections for integrated circuits, highly sensitive photodetectors, and highly efficient solar photovoltaic cells could be realized through such means.
Traditional thin-film growth of direct-bandgap III-V compound materials is not suitable for integration due to a high growth temperature above 600° C. and a high dislocation density when growing on Si. In an effort to make progress towards the goal of integrating optoelectronic devices with Si substrates there has been intense research directed at group III-V nanostructures grown on Si substrates using a vapor-liquid-solid (VLS) growth mode. However, while progress has been made in producing defect-free nanostructures on Si substrates at relatively low temperatures in the range of 430° C.-470° C., the use of metal catalysts such as gold (Au) raises concerns about fabricating such nanostructures using CMOS fabrication techniques. Additionally, small and fragile nanostructure footprints such as those of thin nanowires have made it difficult to fabricate group III-V nanostructures through the use of optical lithography and batch fabrication processes. Thus, there remains a need for optoelectronic devices that can be integrated on Si substrates through the use of traditional CMOS fabrication techniques or techniques that are compatible with Si substrates that contain nearly finished CMOS devices and circuits.